Children’s python hiding under substrate

Hi I’m a first time snake owner and over the past couple of days my juveniles children’s python has been burying itself under the aspen snake bedding he has been eating every time I’ve offered him a fuzzy mice and has shed perfectly the other day he is good to handle will not strike, he is only going into the strike position when putting him back in his cage I’m not sure why.

So 2 days ago I looked in the cage and I couldn’t see him so I was a bit worried I dug up some of the bedding and there he was on the cold side underneath the bedding he usually is under his little hide on the heatmat which is 31c , cool end 24-26c, so I put him back in and fixed the bedding up and he has done it again I opened the cage and removed some of the bedding and he strikes twice and started breathing heavily so I’ve just left him and he hasn’t come out is he brumating since it’s quite cold right now in Sydney or he’s is stressed I’m not sure hope one of you guys can help me out here would be much appreciated he’s due for a feed tomorrow should I feed him or just leave him alone thanks hopefully I’ve given the right info to help me out thanks.